Similar in size to a pink salmon, the coho can be up to 90 centimetres in length and normally weigh between 2.5 and 5 kilograms-but very large coho have weighed up to 12 kilograms. They have a bluish-black body and develop silver sides while in the sea. During the freshwater journey upstream to the spawning grounds, the coho develops a hook in its nose. Coho spawn during the winter months, and the resulting fry can stay in the stream network for up to a year, usually going to the estuaries in the second year of life. Coho are caught in small streams by the Stó:lō, with the help of spears.
Stó:lō stories speak of the origins of the hooked nose of the coho. The story tells of a mating pair of coho swimming upstream, against a very strong current. Needing a break from the tiring swim, the coho formed a hooked nose to catch over submerged branches to rest during the swim. When the coho arrived at the spawning grounds, the nose maintained the hooked shape and the coho decided that this was a great advantage for the upstream trip. Since this event, the coho's nose develops a hook while advancing upstream to spawn.